Yea actually I had to uninstall this because while it changes the CSS, it makes the page load slower. If it didn't change the CSS and only do what the title says (hide threads & replies by poster), I'd keep it. Maybe you can make another version that does just that?

On the mailpage, it also disables the yellow color of new mails.

I'll make it optional to apply the styles.
I'll fix the next mail page later tonight/early tomorrow.

Version 2.2.0.1 changes:

• Removed styles
  
• Bug fixes
  

I found two bugs: If you want to get to them, you need to click show hidden off topic threads and then click show 1 hidden thread. Now there is a button with hide 2 threads. A second bug is, that if you press the button with hide 2 threads also hides all off topic threads again.

PS:Not sure if the buttons are named that way

Should be fixed in version 2.2.0.2 which I recently uploaded.
Version 2.2.0.2 changes:

• Bug fixes